Apparatus for detecting sheet material in a carton machine



L. BROCK May 28, 1963 APPARATUS FOR DETECTING SHEET MATERIAL IN A CARTON MACHINE 5 Sheets-Sheet 1 Filed 001;. 25, 1961 INVENTOR 2 [0 B/QOCK BY May 28, 1963 BROCK 3,091,063

APPARATUS FOR DETECTING SHEET MATERIAL IN A CARTON MACHINE Filed Oct. 25, 1961 5 Sheets-Sheet 2 INVENTOR:

50 Beocz @1572 May 28, 1963 L. BROCK 3,091,063

APPARATUS FOR DETECTING SHEET MATERIAL IN A CARTON MACHINE Filed Oct. 25, 1961 s Sheets-Sheet s Z8 INVENTOR:

50 B/Q K ATTORNEY United States This invention relates to an apparatus for detecting feeding failure in the manufacture of cartons, and more particularly to a mechanism for detecting the proper feeding of foil or tops to the carton.

Heretofore in the art of making paperboard cartons, and particularly the wax-coated cartons used as containers for milk, the cartons have been formed, filled with milk and closed by a single machine. Because flakes of wax frequently separate from the carton and become mixed with the milk, a new paperboard carton has been developed which is coated with a plastic, such as polyethylene, which is more permanently fused with the paperboard than the wax previously used. Moreover, the Sealright-Oswego Falls Corporation has developed their new Seal King machine, which can form, fill and close the new polyethylene cartons. The carton walls are heated to melt the polyethylene so that after the walls are formed, the corners are self-sealing. The top edge of the carton is provided with an aluminum foil tab over which is a flat polyethylene-coated paperboard lid or top, after the carton is filled with milk. The purpose of the foil tab is to facilitate removing a portion of the lid to open the carton.

The operation of the Seal King machine has experienced occasional failure in feeding the aluminum foil and failures in applying the tops to the cartons, without detection.

It is, therefore, an object of this invention to provide a novel apparatus for automatically detecting the failure of the foil feed or carton top feed in a paperboard carton making machine, such as the above Seal King machine.

Another object of this invention is to provide a novel device for detecting the absence of foil at the point of application in a carton making machine.

Another object of this invention is to provide a novel type of mechanism for detecting the absence of the top or lid of a carton along an assembly line.

A further object of this invention is to provide a novel electrical circuit capable of immediately detecting the failure of the feeding of sheet material.

Another object of this invention is to provide a novel electrical circuit for detecting and signaling the failure of feeding of sheet material in either of two simultaneous sheet-feeding operations.

A further object of this invention is to provide a novel electrical apparatus for simultaneously detecting the operation of applying foil and also applying a lid to a paperboard carton during its manufacture, and for immediately signaling and stopping the manufacturing process I upon failure of either foil or carton top application.

Further objects and advantages of the invention will be apparent from the following description, taken in conjunction with the drawings, wherein:

FIG. 1 is a schematic diagram of the electrical circuit made in accordance with this invention as applied to the dual operation of detecting the foil feed and detecting r i i the presence of a carton top in the process of making a paperboard carton;

FIG. 2 is a perspective view, partly broken away, disclosing the mechanism for detecting the presence of foil fed into the path of a carton blank;

FIG. 3 is a section taken along the line 3-3 of FIG. 2;

FIG. 4 is a perspective view of the carton top detector mechanism;

FIG. 5 is an end elevation of the carton top detector mechanism with the carton in section and partially broken away; and

FIG. 6 is a section taken along the line 66 of FIG. 5.

Referring now to the drawings in more detail, the invention is disclosed, for illustrative purposes only, as applied to the component parts of a Seal King machine, made by Sealright-Oswego Falls Corporation of Fulton, New York, such as machine S.P.C. 2l96 1- D, or machine S. P.C. 20760 L.

FIGS. 2 and 3 disclose the foil unit 10, including a stationary table 11 and an upper block assembly 12 hinged at 13 to the table 11. FIG. 3 shows that there is just sufiicient clearance between the table 11 and the upper block assembly 12 to permit the continuous feeding of a polyethylene-coated paperboard carton blank 14 therebetween, in the direction of the arrow. As disclosed in FIGS. 2 and 3, a metallic foil 16, such as aluminum, is fed upwardly through the slot 17 in the table 11 into the path of the forward or pouring edge of the side wall blank '14, and into the slot or passage 18 within the upper block assembly 12. After the foil 16 has reached a pre-determined height in the passage 18, the knife 19 is automatically reciprocated across the slot 17 in order to shear the foil '16. Continuous forward movement of the blank 14 causes the cut foil section 16 to be folded back along both sides of the side wall .14.

In order to detect any failure in the feeding of the foil 16 across the forward end of the blank 14, axially aligned recesses 24 and 2-1 are formed in opposite walls of the passage 18. Located at the closed end of the recessZt) is a light source, such as the light bulb 22, to which electricity is supplied through the lead or line 23. In a similar manner, a photoelectric cell 24 is at the closed end of the recess 21 and supplied with electricity through the lead or line 25. Since the metallic foil is opaque to light, proper feeding of the foil 16 will project it substantially the full height of the recess 18 to block the passage of light from the bulb 22 through the recesses 24) and 21 to the photoelectric cell 24. However, if for any reason the foil 16 fails to enter the recess 18, the passage of light rays from the bulb 22 to the photoelectric cell 24 will be unobstructed. It will also be noted that every time a section of foil 16 is cut by the knife 19 and carried forward by the forward edge of the blank 14, there will be a moment in which light rays will pass unobstructed from the bulb 2 2 to the photoelectric cell 24, even when the machine is operating properly.

Referring now to the drawings in FIGS. 4-6, FIG. 4 discloses completely assembled cartons 28 being moved through the machine by means of the feeder arms 29. The head 39 is adapted to seal the top 31 upon each carton, while the carton top detector mechanism 32 is adapted to detect the presence or absence of a top 3 1, immediately after the operation of the top sealing head 30.

The carton top detector 32 comprises a fork having a 38. Formed on the inner surfaces of the legs 34 and 35 are a pair of opposed axially aligned apertures 39 and 48, adapted to permit the passage of light rays from the bulb 37 to the photoelectric cell 38. The light bulb 37 is connected by the electrical wire or lead 41, while the photoelectric cell 38 is connected by the wire or electrical lead 42.

In order to energize the photoelectric cells and light bulbs of the foil detector and the carton top detector 32, an electrical circuit of unusual design is employed, as disclosed in PEG. 1. The circuit comprises two main power lines 45 and 46 and a grounded line 47, which are supplied with alternating current from any convenient power source, not shown. The lines 45 and 46 are preferably balanced so that each carries an equal load, preferably 60 volts.

The primary coil- 48 of a transformer 49 is connected across the power lines 45 and 46 and is adapted to step down the voltage from approximately 110 to 12 volts. The secondary coil 58 is connected in series with the leads 23, light bulb 22, leads 41, light bulb 37 and the leads 41 and the light bulb 37. It will thus be seen that if any one of the three light bulbs 22, 37 or 37 burns out, no r current will be supplied to any of the other light bulbs.

One side of the circuit 25 of the photoelectric cell 24 is connected in series with the sensitive relay coil 52 and the lead 53 to the power line 46. The other side'of the circuit 25 is connected through the line 54 and resistor 55 to the other power line 45. One side of the relay switch 56 is connected to the line 53, while the other side is adapted to engage and disengage a' contact in the line 57. The lines 54 and 57 are bridged by a resistor 58 in the order of ten kilo-ohms. The relay 52, 56 is so constructed that the switch 56 is closed when the light rays from the bulb 22 are obstructed by the properly fed foil 16, as disclosed by the solid line positions of FIG. 1, under normal operating conditions. Failure of the foil feed permits light rays to energize the photoelectric cell 24 and open the switch 56 to the dashed line position of FIG. 1.

One side of the circuit 42 'for the photoelectric cell 38 is inseries with the relay coil 60, which is also connected through the lead 53 to the power line 46. The other side of the photoelectric circuit 42 is connected through the lead 61 and resistor 62 to the other power line 45. One side of the relay switch 63 is connected to the line 53, while the other side of the switch 63 is adapted to engage and disengage a contact in the circuit 64. The lines 61 V and 64 are bridged by the resistor 65, also having a value in the order of 10 kilo-ohms.

It will be noted that a second carton top detector 32' is included in the circuit in FIG. 1, the circuits being in series with the circuits of the carton top detector 32. The carton top detector 32 is disclosed merely to illustrate that more than one detector'may be employed where there'is more than one assembly line of cartons. Thus, it will be seen that as long as the photoelectric cells 38 and 38' are receiving the unobstructed light rays from their respective light bulbs 37 and 37', to indicate the presence of carton tops 31 upon their respective cartons 28, the relay coil 60 will be energized to close the switch 63 and the circuit 64; However, whenever there is an absence of a top 31 in either carton operated upon by either of the detectors 32 or 32', the forked legs 34 and 35, or 34 and will be permitted to straddle its respective carton wall which will obstruct the light rays between thelight bulb 37, 37' and the photoelectriccell-SS, 38 to open the circuit 42,

35 de-energize the relay coil and open the switch 63 to the dashed-line position disclosed in FIG. 1.

The line 57 is connected in series to an extended coil 67 which is adapted to control an auxiliary switch 68 and a time delay relay switch 69. The other side of the coil 67 is connected through a lead 70 to the power line 45. The auxiliary switch 68 is adapted to reciprocate between one pair of contacts 71 in a circuit which includes the lead 70, the pilot lamp 72 and the lead 73, which is connected to the other power line 46. The relay switch 68 is also adapted to open and close a pair of contacts 74 in a circuit 75 which includes an electronic impulse counter 76 of any conventional make, adapted to be energized every time the switch 68 closes the contacts 74. The counter circuit 75 is connected acros the line 70 and 73.- The circuit is so constructed that, when the relay coil 67 is deenergized by opening the switch 56, the relay switch 68 will be maintained in its raised dashed-line position closing the contacts 71 to illuminate the lamp 72. On the other hand, when the coil 67 is energized by closing the switch 56, the relay switch 68 will be pulled downward to close the contacts 74 to close the circuit 75 and open the circuit through the lamp 72.

The time delay relay switch 69 operates independently of the relay 68. When the coil 67 is de-energized, the switch 69 closes the contacts 78 in the line 79 which 'is connected to the lead 70. When the coil 67 is energized, the relay switch 69 is thrust downward to engage the contacts 80 in the line 81, which is also connected to the line 78. The switch 69 is of the time-delay type, and may be made in any conventional manner, such as incorporating an air bellows which will prevent the relay switch 69 from disengaging the contacts 80 for a period of about one second after the coil 67 is de-energized.

The line 64 branches into the parallel circuits 84 and 85, each of which are connected to their respective relay coils 86 and 87. The other side of the relay coil 86 is connected through the line 88 to the line '81. The other side of'the coil'87 is also connected to the line 81 through the line 89.

The relay coil 86 is adapted to energize a switch having a pair of arms 90 and 91 acting as a unit. The switch arm 90 is adapted to engage and disengage the contacts 92 in the circuit 93, one side of which is connected to the power line 45. The other switch arm 91 is adapted to engage and disengage the contacts 94 in the circuit 95 which, when closed, is adapted to energize the relay for stopping the carton feed mechanism of the machine, not shown.

The relay coil 87 is adapted to also energize a relay switch 97 of the time delay type, similar to 69, but adjusted to disengage the contacts98 after the coil 87 has been tie-energized for a period of about five seconds.-

One contact 98 connects the circuits 79, and 93, while the other contact 98 isconnected through the circuit'99 and the bell 100', or other alarm mechanism, to the power line 46.

The circuit is-so designed that when the relay coil 86 is energized, both switch arms 98 and 91 will disengage their respective contacts 92 and 94, as shown in the solid-line position of'FIG. 1. .Thus, the circuit 95 is 0 energized, the switch 97 will rise to its dashed-line positions of the foil 16, the side walls of the cartons 28 and 28', and all the relays are substantially shown by the solid-line positions of FIG. 1. Under these conditions, the foil 16 is fully extended into the passage 18 to obstruct the rays of light from the bulb 22 to the photoelectric cell 24. The resultant failure of the photoelectric cell 24 to receive light rays will open the circuit 25 to de-energize the coil 52 and permit the switch 56 to close the circuit through the lines 53 and 57, the coils 67, and the lines 70 and 45. The energized coil 67 will activate the switch 68 to open the contacts 71 and close the contacts 74 through the circuit 75. The coil 67 also actuates the switch 69 to close the contacts 80 through the circuit 81 and to open the contacts 78 through the circuit 79.

It will be noted from FIG. 3, that as long as the foil feed continues, a section of foil 16 is cut and engaged by the forward edge of the carton blank 14, and carried through the block 12 to fold over the opposite Walls of the blank 14. Thus, even though the foil feed is in continuous operation, there is a momentary absence of foil 16 in the passage 18, while the carton blank 14 is passing beneath the block 12 and preventing the passage of the next foil section through the slot 17'. During this time, light is transmitted from the bulb 22 through the passages 20 and 21 to energize the photo cell 24. The result of intermittent passage of the toil section 16 into the passage 18 to periodically interrupt the light flow, will cause a similar interruption in the energization of the coil 67, so that the switch 68 is alternating between the contacts 71 and the contacts 74 to cause the lamp 72 to blink every time a foil section 16 is cut and applied to a carton blank 14. Simultaneously, the interrupted circuit 75 energizes the counter 76 to register each carton blank passing beneath the block 12, and consequently indicate the number of cartons fed through the machine.

The energization of the coil 67, also causes the time delay switch 69 to engage the contacts '80 to close the circuit 81. Because the time delay switch 69 is set to remain closed for a period of one second after the coil 67 is de-energized, the alternate energization of the coil 67 caused by the interrupted presence of the foil 16 in the passage 18 will not effect the position of the switch 69, engaging the contacts 80.

Furthermore, during normal operation of the machine, the legs 3435, 3434' of the carton top detectors 32 and 32 will continue to ride over the tops 31 to permit the photoelectric cells 38 and 38' to continuously receive the rays from their respective light bulbs 37 and 37. The energization of the cells 38 and 38 will maintain a closed circuit 42 to energize the coil '60, which is adapted to close the switch 63 and the circuit through the lines 53-, 64, and the parallel circuit through the lines 84, 86, 88, and 85, 87, 89, the closed switch 69, and the line 81 and the return line 70. Thus, with the coils 86 and 87 energized, switches 90 and 91 will remain open to de-energize the stop feed mechanism through the open circuit 95 and to open the circuit 93. Moreover, the energization of the coil 87 will maintain the switch 97 closed against its corresponding contacts 98 to connect the bell circuit 99 and the circuit 79. However, the bell '100 remains de-energized because the circuit 79 is open during the normal operation of the machine.

Assuming the continued application of the carton tops 31, but also assuming a failure in the foil feed mechanism, the foil 16 will drop out of the passage 18 permanently, so that the photoelectric circuit 25 is closed to energize the coil 52 to open the switch 56 to its dashedline position, disclosed in FIG. 1, and therefore open the circuit 57 and de-energize the coil 67. Under these conditions, the switch '68 will rise to close the contacts 71 and illuminate the pilot lamp 72, signaling the failure I of the foil feed. About one second after the de-energization of the coil 67, the time delay switch 69 will rise to open the contacts 80 and close the contacts 78 in the line 79. The opening of the contacts in the line 81, will tie-energize the coils 86 and 87. De-energization of the coil 86, will immediately close both switches and 91 across their respective circuits 93 and 95. The closing of the circuit will immediately actuate the relay not shown, which will cause the carton feed mechanism to stop. The closing of the circuit 93 will immediately cause current to pass through the bell circuit 99, and the closed switch 97, where the current divides between the circuits 93 and 79 to energize the bell 100. The relay coil 87 will also be de-energized simultaneously with the relay coil 86. However, because of the setting of the time delay switch 97 it will not disengage the contacts 98 for a period of about five seconds, at which time the bell is tie-energized. The purpose of this time delay relay is to prevent the continuous ringing of the bell 100 upon failure of the foil feed, since it is believed that a five second audible Warning plus a continuous visible warning from the illuminated lamp 72 will provide an ample alarm.

Assuming a normal foil feed, but assuming the absence of a carton top 31 passing beneath the detector 32', the legs 34' and 35' will be permitted to swing downward to straddle the wall 28, as disclosed by the dashed-line position of FIG. 1. In this event, the carton wall 28' will obstruct the passage of light rays from the bulb 37 to the photoelectric cell 38', opening the circuits 42 and 42 to de-energize the coil 60 and open the switch 63 to its dashed-line position, disclosed in FIG. 1, and thereby open the circuit 64. Under these circumstances, current will continue to flow through the line 57 to periodically energize the coil 67 so that the switch 68 is alternating in its usual manner and the switch 69 is maintained down against the contacts 80. However, with the absence of current through the line 64 and the branch lines 84 and 85, the relay coils 86 and 87 will be simultaneously deenergized so that the switches 90 and 91 will immediately close to stop the carton feed through the circuit 95 and to ring the bell through the circuit 99, the closed switch 97 and the closed circuit 93. It will be noted that under these circumstances that the branch of the bell circuit through the line 79 will remain open, since the switch 69 does not engage the contacts 78. Also, because of the time delay switch 97, the bell 100 also rings for only a period of five seconds.

In the event that both a failure in the foil feed and a failure in the application of one or more carton tops 31, the function of the circuit will be identical to that described when only a carton top is absent, except that the coil 67 will be de-energized to close the switch 68 on contacts 71 to illuminate the lamp 72, and to close switch 69 on contacts 78.

Thus, it will be seen that in the event of a failure of foil 16 to be fed to the carton blank 14, the carton feed mechanism will be immediately stopped, the lamp 72 will be permanently illuminated, and the bell 100 will be energized for a period of five seconds. On the other hand, when a carton top 31 is absent from the top of a carton 28, the carton feed mechanism will immediately be stopped, and the bell 100- will be energized for a period of five seconds. However, the lamp 72 will not be permanently illuminated, but will continue to flash on and off, or remain permanently off or permanently on, depending upon the presence of foil in the block passage 18.

It will be further noted, that if any of the light bulbs 22, 37, or '37 should go out, the entire light circuit will be open so that all lights are out and the over-all circuit will be energized in the same manner as if the absence of a carton top 31 were detected. In other words, the carton feed mechanism is stopped, and the bell 100 would be energized for a period of five seconds.

It will thus be seen that an improved mechanism and unique circuit has been designed for the detection of the failure of the feeding and application of component parts in the manufacture of paperboard cartons, and particularly for -the detection of the absence of foil tabs or carton tops in the manufacture of the carton. Although the mechanical parts of this invention have been disclosed in thedrawings as applied to the Seal King machine for manufacturing milk cartons, it will be understood that the detector'mechanism and the associated circuits may be adapted for any type of machine which manufac tures cartons and containers. 7

It will be apparent to those skilled in the art that various changes may be made in the invention, without departing from the spirit and scope thereof, and therefore the invention, is not limited by that which is shown in the drawings and described in the specification, but only as indicated in the appended claims.

What is claimed is:

1. In a machine for feeding and fabricating cartons having means for feeding sheet material to said carton and means for applying a top'to said carton, a sheet ma terial detector comprising first photoelectric means and a carton top detector comprising second photoelectric means, a signal lamp circuit, an audible alarm circuit, and a carton stop feed circuit, first, second, third and fourth relays, said first and second relays being connected in series and adapted to be energized by said first photoelectric means when said sheet material is detected, said third and fourth relays connected in parallel circuit and adapted to be energized by said second photoelectric means when a carton top is detected, a first switch controlled by said first relay to open said lamp circuit when said first relay is energized and to close said lamp circuit when said first relay is de-energized, a first time delay switch controlled by said second relay to close said parallel circuit including said third and fourth relays when said second relay is energized and to open said parallel circuit and close said audible alarm circuit after said second relay has been de-energized for a predetermined period, a double switch controlled by said third relay to simultaneously open said audible alarm circuit and said stop feed circuit when said third relay is energized and to close said audible alarm circuit and said stop feed circuit when said third relay is de-energized, a second time delay switch controlled by said fourth relay to close said audible alarm circuit when said fourth relay is energized and to open said alarm circuit after said fourth relay has been de-energized for a predetermined period.

2. The invention according to claim 1 including a carton counting circuit, said first switch being adapted to close said counting circuit when said lamp circuit is open and vice versa, means for cutting said sheet material into a section for each carton, whereby the energization of said first photoelectric means and said first relay is interrupted, and an impulse counter in said counting circuit.

3. In a machine for fabricating cartons including means for feeding carton blanks" therethrough and means for feeding opaque foil across the path of said blanks, a table, a block spaced above said table to provide a passage for single blanks, guide means in said table permitting the upward feeding of opaque foil across said passage, a slot having opposed walls in said block opening into said passage for receiving said upfed foil between said walls, means below said passage for periodically cutting said foil, aligned apertures in said opposite walls, a photoelectric cell in one of said apertures and a light, source in said other aperture, signal means, and.

electrical circuit means connected to said photoelectric cell and said light source for energizing said signal means when foil is absent between said apertures.

4. The invention according to claim 3 in which said electrical circuit means includes a time delay relay set to prevent energization of said signal means when said 'foil is absent between said apertures for a predetermined period.

5. The invention according to claim 4 further comprising a stop feed circuit, said time delay relay being connected in said stop feed circuit so that said relay will energize said stop feed circuit to stop the feeding of carton blanks through said passage simultaneously with the energization of said signal means.

6. In a machine for fabricating cartons including means for feeding carton blanks therethrough and means for feeding opaque foil across the path of said blanks, a table, a block spaced above said table to provide a passage for single blanks, guide means in said table permitting the upward feeding of opaque foil across said. passage, a slot having opposed walls in said block opening into said passage for receiving said upfed foil between said walls, means below said passage for synchronously cutting said foil into a strip for engagement by the leading edge of said blank, aligned apertures in said opposed walls, a photoelectric cell in one of said apertures and a light source in said other aperture, a photoelectric circuit connecting said cell and light source, a signal means circuit, a stop feed circuit, a control relay in said photoelectric circuit, a time delay switch operated by said relay, said switch being adapted to close said stop feed circuit and close said signal means circuit at a predetermined time after said relay has been energized by the absence of foil between said cell and said light source.

7. The invention according to claim 6 further comprising a stop feed switch in said stop feed circuit, a stop feed relay and energizing circuit in parallel with said signal means circuit for operating said stop feed switch, said control switch normally opening said signal means circuit and closing said stop feed relay circuit to open said stop feed switch when said photoelectric circuit is de-energized by the normal interrupted presence of foil between said cell and said light source, said control switch being adapted to close said signal means circuit and to open said stop feed relay circuit to close said stop feed switch at a predetermined time after said photoelectric circuit has been energized by the absence of foil between said cell and said light source.

8. The invention according to claim 7 further comprising a second time delay switch in said signal means circuit, a signal delay relay and energizing circuit in parallel with said stop feed relay circuit for normally closing said second time delay switch when said signal delay relay is energized, said second time delay switch being adapted to open said signal means circuit ata predetermined time after said signal delay relay circuit has been dc-energized by the absence of foil between said cell and said light source.

9. The invention according to claim 8 in which said signal means circuit includes an audible alarm adapted to be energized when said signal means circuit is closed.

10. The invention according to claim 6 further comprising a signal lamp circuit and a lamp switch, said lamp switch being operated by said control relay to normally open said lamp circuit and to close said lamp circuit in the absence of foil between said cell and said light source l1. In a machine for fabricating cartons including means for feeding carton blanks therethrough and means for feeding opaque foil across the path of said blanks, electrical means for detecting the presence of foil in the path of said blanks, a signal mean-s circuit, a first relay and energizing circuit, a second relay and energizing circuit, said relays being adapted to be energized by said detector means when foil is detected, a time delay switch controlled by said first relay to normally close said sec- 0nd relay circuit and open said signal means circuit when said first relay is energized, said time delay switch being adapted to open said second relay circuit and close said signal means circuit after said first relay has been deenergized by said detector means when the foil is undetected for a predetermined period.

12. The invention according to claim lrl further comprising a second time delay switch in said signal means circuit adapted to be controlled by said second relay, said second time delay switch normally closing said sig nal means circuit when said second relay is energized and third switch being adapted to close said stop feed circuit opening said signal means circuit after said second relay when said third relay circuit is de-energized by said dehas been de-energized for a predetermined period. tector means when no foil is detected.

13. The invention according to claim 12 further comprising a stop feed circuit, a third switch in said stop 5 References Cited in the file Of this Patent feed circuit, a third relay and energizing circuit in par- UNITED STATES PATENTS allel With said second relay circuit for operating said i third switch, said third switch normal-1y opening said 2351888 Stewart June 1944 stop feed circuit when said third relay circuit is energized FOREIGN PATENTS by said detector means when said foil is detected, said 10 686,600 Great Britain Jan. 28, 1953 

11. IN A MACHINE FOR FABRICATING CARTONS INCLUDING MEANS FOR FEEDING CARTON BLANKS THERETHROUGH AND MEANS FOR FEEDING OPAQUE FOIL ACROSS THE PATH OF SAID BLANKS ELECTRICAL MEANS FOR DETECTING THE PRESENCE OF FOIL IN THE PATH OF SAID BLANKS, A SIGNAL MEANS CIRCUIT, A FIRST RELAY AND ENERGIZING CIRCUIT, A SECOND RELAY AND ENERGIZING CIRCUIT, SAID RELAYS BEING ADAPTED TO BE ENERGIZED BY SAID DETECTOR MEANS WHEN FOIL IS DETECTED, A TIME DELAY SWITCH CONTROLLED BY SAID FIRST RELAY TO NORMALLY CLOSE SAID SECOND RELAY CIRCUIT AND OPEN SAID SIGNAL MEANS CIRCUIT WHEN SAID FIRST RELAY IS ENERGIZED, SAID TIME DELAY SWITCH BEING ADAPTED TO OPEN SAID SECOND RELAY CIRCUIT AND CLOSE SAID SIGNAL MEANS CIRCUIT AFTER SAID FIRST RELAY HAS BEEN DEENERGIZED BY SAID DETECTOR MEANS WHEN THE FOIL IS UNDETECTED FOR A PREDETERMINED PERIOD. 